This invention relates generally to a system for handling storage and inventory control of small parts stored in drawer-like containers and more particularly to a shuttle mechanism for automatically moving said containers into and out of bins or slots in storage racks. Storage and retrieval systems are well known and comprise storage racks for parts being stored on either side of a central aisle. A stacker crane, controlled by an operator through a keyboard, travels the aisle to retrieve and store parts on pallets or in containers lodged in the racks.
U.S. Pat. No. 3,756,433 discloses a shuttle assembly on a stacker crane for moving a cage-like material carrier, suspended from a track or rail, from the transfer rail on the crane to the rail on the storage rack or vice versa. Because the containers run on a rail, it is necessary accurately to align the rail on the crane horizontally and vertically with the rail on the storage rack. This system is rather complex and is not adapted for handling small parts.
U.S. Pat. No. 3,762,531 discloses a shuttle for sliding a flat-sided load from an elevating platform mounted on a load stacker to a bin in a storage rack adjacent the stacker. The shuttle is in the nature of a yoke suspended from a carriage that moves between the elevating platform and the bin. The yoke has side plates disposed at the sides of the load which plates terminate above the platform or floor upon which the load rests. Pusher bars extend between the side plates and are adapted to bear against the end of the load. The yoke moves to and from the adjacent bin to "scrape" the load off the elevating platform and onto the floor of the bin, or vice versa. The pusher bars are mounted on conveyor chains trained on sprockets mounted on the side plates. The pusher bars can be moved from one end of the load to the other by the moving chains. Thus, the load can be pushed toward or away from the bin. The pusher bars cannot pull the load and consequently, must be movable into pushing position at one end or the other of the load.
U.S. Pat. No. 3,921,828 shows a stacker crane and an adjacent storage rack equipped with roller conveyors over which the load travels on a pallet as it moves on and off the storage shelf. The elevator platform also has rollers for supporting the load. A hook is used to pull the pallet from the storage shelf to the stacker crane. Essentially, the load on a pallet is pushed around the conveyors.